Abstract: A method and system for optimizing power consumption of a data center by dynamic workload adjustment. Workload of the data center is dynamically adjusted from a current workload distribution to an optimal workload solution. The optimal workload solution is a candidate workload solution of at least one candidate workload solution having a lowest sum of a respective power cost and a respective migration cost. Each candidate workload solution represents a respective application map that specifies a respective workload distribution among application programs of the data center. Dynamically adjusting the workload of the data center includes: estimating a respective overall cost of each candidate workload solution, selecting the optimal workload solution that has a lowest overall cost as determined from the estimating, and transferring the optimal workload solution to devices of a computer system for deployment.

Abstract: A method and system for optimizing power consumption of a data center by dynamic workload adjustment. At least one candidate workload solution for the data center is generated. Each candidate workload solution represents a respective application map that specifies a respective workload distribution among application programs of the data center. Workload of the data center is dynamically adjusted from a current workload distribution to an optimal workload solution. The optimal workload solution is a candidate workload solution of the at least one candidate workload solution having a lowest sum of a respective power cost and a respective migration cost. Dynamically adjusting the workload of the data center includes: estimating a respective overall cost of each candidate workload solution, selecting the optimal workload solution that has a lowest overall cost as determined from the estimating, and transferring the optimal workload solution to devices of a computer system for deployment.

Abstract: Embodiments relate to a computer system for storing data on a time multiplexed redundant array of independent tapes. An aspect includes a memory device that buffers data received by the computer system to be written to a set of tape data storage devices. The data is written to the set of tape data storage devices in blocks that form parity stripes across the set of tape data storage device. Aspects further includes a tape drive that writes data to one of the set of tape data storage devices at a time in a tape-sequential manner and a processor that computes a parity value for each of the parity stripes. The tape drive writes the parity values for each of the parity stripes to a last subset of tapes of the set of tape data storage devices.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media for on-the-fly deduplication during movement of NoSQL data. In a particular embodiment, a method provides identifying first data items from files in a NoSQL data store and identifying duplicate data items from the first data items. The method further provides deduplicating and repackaging each of the duplicate data items into respective deduplicated data units and transferring the deduplicated data units to a secondary data repository.

Abstract: Embodiments of the invention provide parity logs for raid systems with variable-capacity media. In one embodiment, a system includes a first set of data storage media devices having variable capacity. The storage devices include a data portion of a parity data set for storing write data being striped to the first. The system further includes a second set of data storage media devices having variable capacity. The second set includes a linear address space of blocks for storing a parity portion of the parity data set. The linear address space is written in a log form. The first and second sets comprise at least one array in a RAID configuration. The system writes the parity portion of the parity data set to the second set, which enables each storage device among the first set to be written to full capacity.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A state of a filesystem associated with a para-virtual I/O system is updated, which includes performing semantic journaling in support of the update. The semantic journaling includes writing one or more data blocks and logging metadata updates to a journal. A cache flush request is received and classified based on semantic information of the system. The classification provides an order of commands for processing the received request. The classification is converted into an order of committed writes, and the order of committed writes is processed. The processing includes enforcing the order of committed writes to provide a consistent virtual disk image.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media for infinite versioning by automatic coalescing. In a particular embodiment, a method provides determining an age range for a plurality of data versions stored in a secondary data repository and identifying first data versions of the plurality of data versions that are within the age range. The method further provides determining a compaction ratio for the first data versions and compacting the first data versions based on the compaction ratio.

Abstract: Embodiments of the invention relate to receiving a write request that includes a write data and an address of a target block in tertiary storage. In response to the write request, a write-miss is detected at a cache located in persistent storage. Based on detecting the write-miss, the write data and associated metadata are written to a fast write storage location and the write request is marked as complete. In addition, the target block is retrieved from the address in the tertiary storage and stored in the cache. Contents of the fast write storage location are merged with the contents of the target block in the cache.

Abstract: A computer identifies a plurality of data retrieval requests that may be serviced using a plurality of unique data chunks. The computer services the data retrieval requests by utilizing at least one of the unique data chunks. At least one of the unique data chunks can be utilized for servicing two or more of the data retrieval requests. The computer determines a servicing sequence for the plurality of data retrieval requests such that the two or more of the data retrieval requests that can be serviced utilizing the at least one of the unique data chunks are serviced consecutively. The computer services the plurality of data retrieval requests according to the servicing sequence.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media for data lineage based multi-data store recovery. In a particular embodiment, a method provides identifying first data in a first table of a plurality of tables stored in a plurality of data stores and restoring the first data to a first correct version of the first data in a prior version of the first table. The method further provides identifying a second table of the plurality of tables that descends from the first table and includes second descendent data that stems from the first data. The method also provides restoring the second descendent data to a second correct version of the second descendent data in a prior version of the second table.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A consistent para-virtual I.O system architecture is provided with a new virtual disk interface and a semantic journaling mechanism. The virtual disk interface is extended with two primitives for flushing and ordering I/O, both of the primitives being exported to para-virtual I/O drivers in a guest operating system. The ordering primitive guarantees ordering of preceeding writes, and the flushing primitive enforces order and durability. The guest drivers selectively uses both of these primitives based on semantics of the data being persisted from the para-virtual cache hierarchy to physical disk. The order of committed writes is enforced in order to enable a consistent start recovered after a crash.

Abstract: Embodiments of the invention relate to cache management of sequential write storage. Cache states of cache blocks in cache storage are tracked. The tracking incudes creating a migration candidate list that organizes the cache blocks into virtual volumes. Based on determining that a cache migration threshold has been reached, at least a subset of the cache blocks are selected from the migration candidate list for migration. The selected cache blocks are ordered into a sequential order based on the migration candidate list. At least a subset of the selected cache blocks are migrated in the sequential order, the migrating including writing contents of the selected cache blocks to the sequential write storage.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media to enhance the organization, storage, and retrieval of data. In a particular embodiment, a method provides storing a plurality of incremental data versions in a data repository and maintaining first time information for data items in each of the incremental data versions. The method further provides identifying a first data version of the plurality of incremental data versions and writing data in the data repository to create a second data version based the first data version. The method then provides second time information associated with the creation of the second data and creation of the first data version.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable storage media for time-based storage and retrieval of data items. In a particular embodiment, a method provides receiving a point-in-time data request. Using metadata associated with data items stored in a secondary data repository, the method provides determining a mapping between the point-in-time data request and one or more of the data items. The method further includes providing the one or more data items in response to the point-in-time data request.

Abstract: A computer identifies a plurality of data retrieval requests that may be serviced using a plurality of unique data chunks. The computer services the data retrieval requests by utilizing at least one of the unique data chunks. At least one of the unique data chunks is utilized for servicing two or more of the data retrieval requests. The computer determines a servicing sequence for the plurality of data retrieval requests such that the two or more of the data retrieval requests that are serviced utilizing the at least one of the unique data chunks are serviced consecutively. The computer services the plurality of data retrieval requests according to the servicing sequence.

Abstract: Embodiments relate to a computer system for storing data on a time multiplexed redundant array of independent tapes. An aspect includes a memory device that buffers data received by the computer system to be written to a set of tape data storage devices. The data is written to the set of tape data storage devices in blocks that form parity stripes across the set of tape data storage device. Aspects further includes a tape drive that writes data to one of the set of tape data storage devices at a time in a tape-sequential manner and a processor that computes a parity value for each of the parity stripes. The tape drive writes the parity values for each of the parity stripes to a last subset of tapes of the set of tape data storage devices.

Abstract: Embodiments of the invention provide parity logs for raid systems with variable-capacity media. In one embodiment, a system includes a first set of data storage media devices having variable capacity. The storage devices include a data portion of a parity data set for storing write data being striped to the first. The system further includes a second set of data storage media devices having variable capacity. The second set includes a linear address space of blocks for storing a parity portion of the parity data set. The linear address space is written in a log form. The first and second sets comprise at least one array in a RAID configuration. The system writes the parity portion of the parity data set to the second set, which enables each storage device among the first set to be written to full capacity.

Abstract: Embodiments of the invention relate to a para-virtual I/O system. A consistent para-virtual I.O system architecture is provided with a new virtual disk interface and a semantic journaling mechanism. The virtual disk interface is extended with two primitives for flushing and ordering I/O, both of the primitives being exported to para-virtual I/O drivers in a guest operating system. The ordering primitive guarantees ordering of preceeding writes, and the flushing primitive enforces order and durability. The guest drivers selectively uses both of these primitives based on semantics of the data being persisted from the para-virtual cache hierarchy to physical disk. The order of committed writes is enforced in order to enable a consistent start recovered after a crash.

Abstract: Embodiments of the invention relate to cache management of sequential write storage. Cache states of cache blocks in cache storage are tracked. The tracking incudes creating a migration candidate list that organizes the cache blocks into virtual volumes. Based on determining that a cache migration threshold has been reached, at least a subset of the cache blocks are selected from the migration candidate list for migration. The selected cache blocks are ordered into a sequential order based on the migration candidate list. At least a subset of the selected cache blocks are migrated in the sequential order, the migrating including writing contents of the selected cache blocks to the sequential write storage.

Abstract: A method and associated system for continuously optimizing data archive management scheduling. A flow network is modeled, which creates vertexes organized in multiple levels and creating multiple edges sequentially connecting the vertexes of the multiple levels. The multiple levels consist of N+1 levels denoted as LEVEL0, LEVEL1, . . . , LEVELN, wherein N is at least 2, wherein LEVEL0 includes a source vertex, wherein LEVEL1 includes at least one task vertex associated with at least one archive management task, wherein EDGEK is directed from the vertex of LEVELK-1 to the vertex of LEVELK for K=1, . . . , N, wherein EDGE1 indicates that a first task associated with a first task vertex of LEVEL1 is scheduled by a job scheduler, and wherein EDGE1 has a first weight equal to a time unit to perform the first task.